The Springbok Sevens side on Friday outclassed Great Britain to win Pool C at the Dubai Sevens.
The Blitzboks ran in five tries to win 31-12, after leading 12-7 at half-time.
MATCH CENTRE | Dubai Sevens
Skipper Siviwe Soyizwapi was on hand with another brace of tries, while Muller du Plessis, Impi Visser and Branco du Preez also crossed the whitewash.
The Blitzboks, though, will be worried over the fitness of Du Plessis, who was stretchered off on the stroke of half-time with what looked like a serious ankle injury.
While he was satisfied with the winning results, Powell mentioned afterwards his charges can still improve on their cohesion.
"The individuals played well but we haven’t played well as a team yet," said Powell.
"One of the things I want us to step up tomorrow is to play well as a team, on defence and attack. Also, conceding five tries on the opening day is something that we will have to look at closely."
Powell gave newcomers Shilton van Wyk and Tiaan Pretorius their first of World Series action.
"It was nice to give them a taste of what it's like to play at this level," said Powell.
"The standard (of play here today) was better than the opposition we faced in Canada, so it was a good test for them. So, some areas to improve on, but we laid a good foundation for day two."
In Saturday's Cup quarter-finals, the South Africans will face Australia, who were runners-up in Pool A. (08:50 SA time).
SA 31 (12)
Tries: Muller du Plessis, Siviwe Soyizwapi (2), Impi Visser, Branco du Preez
Conversions: Ronald Brown (3)
Great Britain 12 (7)
Tries: Robbie Fergusson, Ross McCann
Conversions: Frederick Roddick